1. Field of the Invention
The present invention relates to the art of paper manufactures and converting of paper products. More specifically, the present invention relates to the art of converting paper flatware.
2. Description of the Prior Art
The present state-of-the-art process and apparatus for manufacturing paper plates and other paper flatware relies upon a process step series performed upon paperboard of 0.014 inch or more caliper paper by a multiple work station machine such as that illustrated by FIG. 1 of the drawing. A reeled web 10 of such paper W at one end of the machine provides a continuous material supply into the first machine work station 30 which is a cutter of the reciprocating die and anvil type. With each reciprocation cycle of the die 31, an increment W' of web length driven by an upstream drive station 20 passes between the withdrawn die pressure foot 32 and anvil 33. As the cutter drive shaft 38 rotatively advances the reciprocation eccentric 35, a shearing knife 34 along the in-feed edge of the resiliently mounted pressure foot 32 severs web increment W' from the supply continuum.
Further into the reciprocation cycle, the circular perimeter of die 31 shears a flat disc shape D between the face edge corner of such die and the end corner of a diematching anvil cylinder. The resulting disc D which constitutes a plate blank falls internally through the anvil 33 cylinder onto a slide-way 36 for advancement to the next machine work station whereas the remaining trim T of web increment W' is pushed or falls onto a disposal conveyor 37 when released by the cyclically withdrawn pressure foot 32.
In the case of prior art machines, the disc slideway 36 guides the discs D directly into a heated forming press 40.
Like the cutting die 30, the forming press 40 comprises a stationary anvil 41 having a recess or concavity formed therein. Although not illustrated in detail, the concavity shape conforms to the convex or underside face of the plate product.
In reciprocal alignment with the forming anvil 41 is a forming die 42 having a convex pressing face 43 conforming to the upper or concave face of the plate product. This forming anvil 41 is resiliently biased away from the die 42 and against the surface of a cam 44 driven rotatively by drive shaft 45. Rotation of the cam 44 reciprocates the die 42 against the bias of springs 46.
Upon ejection from the forming anvil 41, finished plate P follows a slideway 48 to a vertical stacking station 50.
To multiply the productivity of such aforedescribed paper plate machines, multiple parallel process lines are provided within the same machine frame. Accordingly, a duplex machine would, on the same die frame 30, have two, side-by-side cutting dies 31 for cutting two discs D from a single web increment W' of sufficient width. The parallel, side-by-side discs D would advance together into a pair of side-by-side press die 42 and anvil sets 41.
Although only one reel 10 and feed web W is shown, it is known to simultaneously feed up to four superimposed webs into the machine. Assuming a duplex machine having two cutting and forming lines, a quadra-ply feed web would produce eight plates per cycle. Such multiple feed ply practice is limited, however to non-registered cutting and forming due to the fact that with such an arrangement, positive feed control may be maintained only over the outermost ply in running contact with a register controlled drive wheel 21. Relative slippage will occur between the lower plys to defeat any pre-set registration alignment but of insufficient consequence to an unregistered pattern cut.
If the plate product is to be cut and formed pursuant to a registration aligned pattern such as is required of a concentric rim plate pattern set against a solid color base field, the plate pattern is previously printed on the web in a rectangular pattern of such rims. Across the web W width, the rims are given a lateral or cross-direction center spacing conforming to the lateral center spacing of the side-by-side duplex cutters and forming dies. Longitudinal of the web W, the rim patterns are center spaced to conform with the length of web increment W'. In addition, however, spacing marks, placed with dimensional precision relative to the rim pattern center, are simultaneously printed along the trim edge of web W. Such spacing marks constitute photo-targets for a photosensory controller 22. By well known prior art means, photosensory controller 22 responds to the passage of a spacing mark to control the rotation of drive wheel 21 whereby the correct length of web is displaced by wheel 21 to center the rim pattern between the cutting die 31 and anvil 33 cylinder. Accordingly, the plate blank D emerges from the cutting station 30 with the printed rim pattern positioned in exact concentricity with the circular perimeter of the plate rim.
From the foregoing, it will be noted that maximum machine productivity of a registered pattern is only one fourth that of an unregistered pattern due to an inability to sustain the lower three plys of a quadra-ply web feed line in registration with the cutting die 31.
Conceivably, a two, three or four ply web feed line could be constructed to register control each of the corresponding feed webs. However, the relative product value and market demand rarely justifies such capital expense. Moreover, such a web feed system would require considerably more production floor space to house.
It is, therefore, an object of this invention to at least double the presently available register formed productivity of such aforedescribed machinery without resort to multiple feed web registration control systems.
Another object of this invention is to at least double the productivity of a paper plate forming machine having a registered, single web in-feed.
Another object of the invention is to teach the construction and operation of a paper plate forming machine which may be quickly changed from unregistered multiple-ply web in-feed operation providing a maximum unregistered productivity to a registered single-web operation providing a productivity of approximately half the maximum.